A thrust return pedal is used in the field of driving assistance for a motor vehicle and therefore serves as an interface between the vehicle and its driver.
This type of pedal is for example used in the field of speed regulation. There are regulators which automatically manage the speed of the vehicle. It therefore suffices to select a cruising speed and an electronic management system ensures that the vehicle is kept at this speed. Speed regulation can also be carried out by creating a hard point during the depression of the accelerator pedal. When the set speed is then reached, the driver feels a hard point in this pedal and he thus knows that the set speed has been reached.
The thrust return pedal acts in this case like a luminous or audible alarm which warns the driver. The driver is then free to take note or not to take note of this alarm. This type of information means has the advantage of being perceived only by the driver and not by the other passengers.
The document FR 2 685 667 discloses a thrust return pedal. In the disclosed device, a servomotor controlled by an electronic unit acts on the pedal by modifying a return force which depends on the interval between the actual speed and the set limit speed value. The mechanism described is such that when the set speed has been reached the mechanism causes the pedal to gradually harden. The stiffness of the thrust return mechanism varies progressively and it is found that the hard point takes effect slowly. Because of this, the feeling created in the driver's foot is not very pleasant.
The mechanism described in this document acts by only varying the stiffness of the pedal return mechanism. In particular, it does not allow instantaneous control of the thrust to be applied to the pedal nor does it allow rapid vibrations to be produced in the pedal. Moreover, in the event that the thrust return mechanism should malfunction, it may arise that the return force with the maximum stiffness is then applied continuously to the pedal. This does not affect the safety of the vehicle but it is uncomfortable.
Finally, the mechanism described has a relatively large overall size such that it cannot be integrated into a pedal module as currently fitted to many motor vehicles.